The higher the number the rarer the card. They came in series, so Joe Namath 03-20 is card number 20 in series 3. 23-04, Nolan Ryan $30, 61-16 Roberto Clemente$30, 72-17 Joe Paterno $30, 78-02 Magic Johnson $250, 77-10 Wayne Gretzky $300, 74-18 Larry Bird $350 are some of the most valuable cards in an old price guide I have. There are a few basketball cards I'm interested in if you are trading any of these.